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Re: CreativeWork can't be a Product?

From: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Date: Tue, 8 Oct 2013 14:23:02 +0200
Cc: Dan Scott <dan@coffeecode.net>, public-vocabs@w3.org, aaranged@gmail.com
Message-Id: <41197528-95C4-4FC2-B081-4BA4B37C0004@ebusiness-unibw.org>
To: chilly_bang@yahoo.de
Hi Chilly,
it is not a bug, but a feature - schema.org follows the idea that if you need multiple types (not exactly, but roughly what you mean with inheritance), you shall represent that at the *instance* level, not in the *schema*.

The choice is very pragmatic and effective: If you have certain types in a vocabulary that are not disjoint, you would otherwise have to materialize all (or at least a lot of reasonable) combinations. That would blow up the vocabulary significantly. Plus, many of the types we are discussing here represent *roles*, not rigid, essential types. So a book that is described as a product is simply the intersection of Book and Product. A book that is described in a non-commercial context is just a book.

Since the semantics of Product is essentially that of a Thing used as the object in an offer, a large share of schema.org types would have to appear as specializations of Product.

Multiple typing at instance level is NOT a workaround. It is a flexible modeling paradigm, rooted in the notion of facets.

Martin
 
On Oct 8, 2013, at 12:57 PM, Chilly Bang wrote:

> Hello!
> 
> I read all your answers  - many thanks for clarifying this issue. As i see there are mainly two approachs to get thing done: "two types approach" and using of additionalType.
> 
> It is very helpful to have such workarounds, but they are only workarounds, not a "right" solution. This issue seems to be solvable with just simple change of type passage structure/inheriting, namely: one things must be maked possible, CreatieWork type must can inherit Product type. I mean such inheritance is a simple thing, which is even partly present, on other place: CreativeWork can inherit Offer, but why not Product? Making it possible would make such workarounds like "two types approach" redundant - they are indeed redundant cause of impossibility of inheritance, which is possible on another, near place.
> 
> Schema.org has pretty clear structure, maintaining of it provides Schema.org to more users and makes the implementing more easy, selfexplaining and issueless. But if one thing is possible on one place, on another similar place is this not possible and needs workarounds so the whole clear structure of Schema is confused. It is just my feeling.
> 
> 
> --------------------------------------------
> Dan Scott <dan@coffeecode.net> schrieb am Mo, 7.10.2013:
> 
> Betreff: Re: CreativeWork can't be a Product?
> An: "Chilly Bang" <chilly_bang@yahoo.de>
> CC: public-vocabs@w3.org
> Datum: Montag, 7. Oktober, 2013 22:37 Uhr
> 
> On Mon, Oct 07, 2013 at 09:16:01PM
> +0100, Chilly Bang wrote:
>> Hello!
>> 
>> i'm busy at the moment with marking up with microdata of
> an online bookstore and realized the following dilemma:
>> if a page is about describing and selling of a
> CreativeWork/Book, so i come to selling properties with
> itemprop="offers" itemscope="" itemtype="http://schema.org/Offer". But on this way i can't
> describe the book i sell like Product, with product's
> properties - i can't find any passage from CreativeWork to
> Product. There is in fact a passage from Offer to Product,
> with itemprop="itemOffered" itemscope="" itemtype="http://schema.org/Product", but repeating isn't a good
> way, beside of this it isn't easy to get such passage into
> html, even with itemref.
>> 
>> I see no possibility to go the way
> CreativeWork->Product->Offer (or
> CreativeWork->Product and CreativeWork->Offer), but
> only CreativeWork->Offer, or Product->Offer.
> CreativeWork can't be a Product or am i wrong?
>> 
>> Imho CreativeWork surely can own product's properties so
> it must gladly have a passage from any CreativeWork property
> to Product.
> 
> You can just use both types in the itemtype declaration, for
> example,
> itemtype="Book Product".
> 
> We're doing this in the #schemabibex group to express offers
> for a given
> item. And Martin gave a wonderful example of this approach
> on this list
> just a few days back at
> http://lists.w3.org/Archives/Public/public-vocabs/2013Sep/0206.html
> 
> 

--------------------------------------------------------
martin hepp
e-business & web science research group
universitaet der bundeswehr muenchen

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Received on Tuesday, 8 October 2013 12:23:27 UTC

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